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SEER Inquiry System - Report
Produced: 09/20/2026 1:09 AM
Question 20081114
Inquiry Details
References:
2007 SEER Manual, 2
Question:
Reportability--Brain and CNS: Is hygroma reportable? See Discussion.
Discussion:
Benign brain guidelines indicate that named tumors that have been assigned an ICD-O-3 code are reportable. However, per I&R: "Most cystic hygromas (9173/0) are fetal malformations and occur in patients less than two years old. If this patient was an adult, they are primarily treated with surgery. Hygroma (used in a general sense) is a response to trauma (i.e., subdural hematoma) and as such, is not a "new growth" and would not be reportable either as a cyst or as a neoplasm. Unless the patient had some sort of operation, I'd hesitate to include the case as a reportable benign tumor."
How is the cancer registrar to distinguish between reportable and non-reportable hygromas? Example: Brain MRI showed diffuse cerebral volume loss and incidental bilateral frontal subdural hygromas (histology code 9173/0).
Reference: I&R 14825
Answer:
Hygromas are not reportable. This instruction will be added to the next revision of the benign brain rules.
According to an expert in the field, hygromas are not neoplastic. Hygromas are cystic dilations of a localized subarachnoid or subdural accumulation of clear fluid related to an excess accumulation of CSF, typically related to an old hemorrhage that somehow prevents reabsorption of CSF.
